Teaching An Old Mosquito New Tricks

How behavioral resistance could spell trouble

Scientists are already aware that using too much of a good thing can lead to resistance. Think of common bacteria, for example. It used to be a round of antibiotics could cure much of what ails us. Today, though, words like super-bug or super-bacteria can send shivers down the spines of researchers, doctors, and patients.

There may be another type of resistance on the horizon and one that science is just learning to understand. It’s called behavioral resistance – different than learned behavior and biological resistance – and it can change the battle plan in the war on mosquitos.

The allure of mosquito netting

In travel brochures and high-gloss fashion magazines, a bed draped with mosquito netting conjures up the romance. Gauzy and from another time and place, it creates a cocoon of intimacy.

In many parts of the world, though, that netting is the difference between life and death. In developing nations, where lack of funding leads to a lack of medications and anti-malarial drugs, mosquito netting is a major weapon in the fight against mosquito-borne illnesses.

Insecticide-treated nets (ITNs) are often hung from frames over beds, desks, and even cooking and eating areas. While mosquitos cannot penetrate the netting, the female mosquito’s proboscis (or mouth) can – so the frame is a way of keeping the netting away from human skin. The number of malaria cases where nets are used has dropped by 20%.

Over time – through washing or exposure to sunlight – the insecticide breaks down. Depending on the insecticide used, netting can last from six months to three years.

Mosquito netting and behavioral changes

To better understand how organisms – in this case, mosquitos – can change over time, it’s important to revisit a few key concepts from high school biology class.

A learned or behavioral reaction is not a change in genetics. Consider the idea of touching a hot stove. Once a child feels the heat coming from a stove top, the child learns that he can be burned and so avoids touching a hot stove.

Biological resistance is a genetic change. The bacterium that causes an infection, for example, can be treated with Medicine A. While most of the bacteria will die off with treatment, some may have a mutated gene that prevents Medicine A from working. These bacteria will then produce other bacteria with that mutated gene, and so on and so on, until the mutated gene is quite predominant, making Medicine A ineffective.

Behavioral resistance is also a genetic change, in which an organism’s behavior within its environment is altered. The behavioral change is not learned but is shared by the entire community.

Changing mosquito behavior

Studying insect behavior, particularly mosquitos, isn’t easy. Various factors, such as geographical area, lack of a control group, and difficulty in distinguishing reaction from resistance, can all interfere with determining behavioral resistance.

The cause for alarm, though, is based on a few pieces of research.

A study of corn rootworm uncovered the discovery of behavioral resistance. This particular pest lays its eggs in cornfields so its larvae will emerge the following year to feed on the roots of corn plants. Farmers were able to combat the problem by instituting crop rotation. In time, rootworms had changed. One species began hatching every other year, while another species invaded neighboring soybean fields to wait for them to switch over to corn.

Mosquitos in the South Pacific (where mosquito netting is used) have changed their predatory behavior to outside and earlier in the day, where and when people are less likely to be surrounded by ITNs.

The battle for the future

In light of these discoveries, researchers all agree that prevention is still the best medicine. ITN’s are a crucial tool in the fight and should continue to be used. Closer to home, Platinum Mosquito Protection believes a proactive stance is necessary. That means knowing your property and eliminating all opportunities for standing water.

To supplement your own vigilance, you may also want to consider an automatic misting system for your property. We offer a variety of mosquito control solutions that can help keep you and your family safe. For a free consultation, complete our online form.